Ba mond dubois



Feb. 24, 1931. G. GAUTIER ET AL 1,793,605

CATHODE FOR ROTARY FLAME ARCS Filed April 29, 1929 Patented Feb. 24, 1931' UNITED- ew s GEORGES GAUTTER. AND neon LE BOZE-C, or cwmeeq eaaapairme DUBOIS, or

ASNIERES, FRANCE oATHonn ron Korma FLAME .ARCS

. Application filed April 29, 1929, Serial No. 359,030, and i1; France May 5, 1928.

Our invention relates to a new form of cathode for rotary flame arcs of the kind dey scribed in the UIS. A. Patents No. 1,328,304 of December 2nd, 1919, and No. 1,390,456 of September 13th, 1921. I

The older apparatus comprises a hollow ring-shaped metallic cathode so-called ring cooled by water or any other cooling fluid.

This ring is carried in a support provided on the outside with coils through which passes the are current. They produce the magnetic field in parallel with thecarbon the eflect of which is designed to produce the V motive power which causes the arc flame to rotate about the crater.

This arrangement is most advantageous for low intensities (25 amperes for example) but in the case of higher intensities the steadiness is not satisfactory. It has been found that this is due to the great tendency on the part of the flame to rotate on the-front part of the cathode, as electrodynamic forces tend more and more to cause the lengthening of the flame towards the front and the break follows. As these phenomena do not occur with small cathodes used under 25 amperes it has. been thought that the reason of this was the increase in the diameter of the winding that creates the field. The reason appears to be in the distribution of the magnetic field which is more uniform in the middle zone as the diameter of the coils is larger.

The use of coils having the smallest po sible diameter produces a field which de? creases very rapidly towards the front and the back of the crater, the lines of force of the same diverging, on both sides of the middlezone. 7 V v In the case othigh intens ties 'we 'utlhze 1 thick carbons, a longer are and a larger water delivery, consequently the cathodes must be relatively large.

Our invention consists in'placing the winding which produces the field inside therecess provided for the circulation of the cooling fluid thus allowing the utilization of a wind- 1 Zing having a very small diameter. V

The space thus lost for the fluid is small because rew coils only of the wire -w1ll be suflicient and owing to the strong cooling of said winding the wire may be, fine. Moreover i the insulation may beproduced without difficulty because the ohmic drop is .lessthan 0,1 volt for this short length of wire. Electrolysis of the water does not take place and 1 the currents shunted through the water; con- Stltlltefl fraction of the main current which maybe disregarded. I

edge without'tending in any way to pass in This gives steadiness tov the arc and to thebrilliancy, anda luminosity front of the crater.

to the crater which may be absolutely compared to that of small arcs'based onthe same principle.

Fig. 1 of the appended drawing is a diagrammatic sectional view which-shows by 'way of example a mode of execution of a cathode according to the present invention.

Fig. 2 is a vertical, central sectiont-hereof. As will be seen in said drawing the winding E having one end connected in solid contact at b, by soldering or in any suitablemanner is container in the ring shaped parta in which the cooling fluid circulates, the other end of said winding passing out of the ring through a stuffing box 0 the water tight packings of which'are insulating.

Having thus described our invention, what we claim and desire to secure by Letters Patent is: i

1. A cathode for rotary flame are which comprises a hollow annular ring and a winding within the same, the axis of said winding being that of the ring, the winding being connected tosaid ring for the passage of the electric current thereto. I i

2. A cathode for rotary flame are which comprises a hollow annular ring in which a cooling fluid flows continuously anda winding immersed in said fluid,.the electric current flowing through said winding the axis of" the latter being the same as that of the ring.

8. A cathode for rotary flame are which 4 comprises a hollow annular ring with inner circulatlon of a cooling fluid and a, winding placed in the interior of the ring through ace which said fluid flows, the axis ofthe winding being the same asthat of the ring, and the Winding being connected at one end in solid contactwith the ringv while its other end passes out of said ring through a stufiing box. In testimony that we claim the foregoing as our invention we haveigigned our names.

7 GEORGES GAUTIERQ LEON BQZECt RAYMOND DUBQIS. i 

